Vacuum drying apparatus.



A. RAVAUTTB. VACUUM DRYING APPARATUS. APPLICATION FILED FEB.24, 1912.

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Patented June 16, 1914.

A. RAVAUTTE. VACUUM DRYING APPARATUS. APPLIUATION FILED rEB .z4, 1912.

1,100,028, Patented June 16, 1914.

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0 n Eg?.

Intentar.

UNITED STATES PATENT oFFioE.

ALBIN RAVAUTTE, OF MARSEILLE, FRANCE, ASSIGNOR T0 ALBIN RAVAUTTE, OF MARSEILLE, FRANCE, EMILE CHARLES ALBERT FLEURENT, 0F PARIS, FRANCE, AND SOCIETE ANONYME DES ETABLISSEMENTS EGR-0T, OF PARIS, FRANCE, A COR- PORATION OF FRANCE.

To all whom it may concern.' Beit known that I, ALBIN RAvAU'rrE, citizen of the French Republic, residing at MarV seille, Department of the Bouches du Rhne,

in France, have invented certain new and:

useful Improvements in and Relating to Vacuum Drying Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the invention, such asI will enable others skilled in the art to which it appertains to make and use the same.

The invention has for its object the construction of an apparatus designed to carry out in a continuous manner, and in an atmosphere maintained at a pressure below` der treatment and at the same time' to dis-` place them with a slow `and uninterrupted movement. The chamber is connectedto a` vacuum pump insuch a manner that the water vapor will be exhausted and the a-ir which is withdrawn passesbefore issuing from the chamber, into a rotating filter which stops the particles of powder. The operation being carried out at a temperature which is not very` high, is particularly adapted for the treatment of cereals, of leguminous bodies and their derivatives, flours, meals, greats and the like.

In the accompanying drawings: Figure 1 is an end view of an apparatus constructed according to the invention: Fig. 2 is a' longitudinal sectional view of the saine: Fig. 3 is a sectional view perpendicular to the plane of Fig. 2: Fig. 4 is a similar'sectional view, the cleaning apparatus being` supposed to be removed: Fig. 5 is a sectional view of a rotary valve having two cells: Fig. 6 shows a longitudinal section of. the preceding figure: Figs. 7 and 8 are views similar to Figs. 5 and 6 respectively of a rotary valve having a single cell.l

Referring to Figs. 1 to 4 the apparatus consists essentially of a drying chamber Y surrounded by a steam jacket Z. At the lower part of the chamber Z are arranged heating pipes 21. At the lower part of the drying chamber is arranged a spirally coiled Specification of Letters Patent.

` Apipe 22 fixed on a rotating frame 24. The

coiled pipe communicates with the hollow l p Patented June 16, 1914. Application filed February 24, 1912. Serial No. 679,543.

axle 25 the ends of which are mounted in two boxes A and B communicating with the steam chamber Z. The tightness of the joints is obtained by the use of suitable stuffing boxes. On the frame 24 are placed small rubbers or brushes 2,6 inclined to the axis and arranged in such a. manner as to sweep the whole length of the chamber.

- These small rubbers or brushes serve, to

gether with the coiled pipe, to carry the material from one end of the chamber to the other.V The frame 24 receives a rotatory movement from a shaft 15 by means of a chain passing over sprocket wheels 16 and 17. This shaft is itself driven by gears from a motor shaft 1. The upper part of the drying chamber contains a rotary filter W made in the following manner: Upon a perforated tube C are xed two star-like cheeks D. The peripheres of these two cheeks serve as' a support for perforated plates E; a wire gauze applied to the external surface of the plates E completes the body of the filter. It is upon this wire gauze that the filtering cloth, properly socalled, is applied. The central tube C opens at one of its ends into a chamber F. It is closed at the other end by a plate H fixed upon the axis of the cheeks D. The tube C is fixed to a shaft I which reoeivesrotary movement from a shaft 7 by means of a worm wheel20 actuated by a worm driven by wheels 18 and 19. The shaft 7 on which the chain wheel 18 is'secured is actuated by the'motor shaft 1. In the interior of the tube 'C is placed a helical strip O. The chamber F is closed externally by a movable cover upon which isfixed a trough J of semi-cylindrical form. Said chamber is further provided at its upper part with a neck Q in connection with a condenser and exhauster, and with a semi-circular baflie R, this latter producing a lengthened path favorable to the deposit Aof the dusty particles.

The continuous cleansingof.v the filter tissue is obtained in the following manner: Pins K fixed on one ofthe wheels I-I make contact with a nger L which, during rotation of the lter rotates the shafts M and scale in Figs.- 7 and S Y valves' for the' supply andV springs V. The shafts M and N carry at intervals along their length small flexible straps or tapping elements P. As soon as, by the rotation of the filter, one of the pins K has left the finger L, theshafts M and N, returned to their position of rest by the spring V, impress a jerking movement upon the straps P which are caused to strike simultaneously the one set on the right hand side and the other set on the left hand side of one of the branches of the l'ilter; the two faces of the same branch of the star are thus Vstruck at each revolution of the'ilter. The particles shaken off fall back directly into the lower part of the drying chamberV The particleswhich may have traversed the filtering cloth fall back into the trough J, andare carried 'by the helical strip O into thev lower part of the chamber F from whence they can beL extracted by removing the plug X. j

The apparatus comprises two rotary valves, the portsand over-lappings of which are constructed insuch a manner as to" shut 01T all direct communication of the interior of the drying chamber withy theouter air. f In FigfQ are illustrated valves having one cell these valves are represented on alarg'er The rotary part is arranged in a Xed casinghavingtwo openings, the oneV 30 for chargingand the other 3l' for discharging.A The rotary portion has trunnions' 33- and 341i supported infbearings arranged on the ends of the' iiXed casing. One of these trunn'ions' 34 is furnishedwith a device fortransmitting to it a rota-ry'mcvement, the other 33 carries;V a cross-piece T which can be displaced laterallyl so asto give an a-'X'i'almovement to the rotary valverllhis displacement, obtained by means ofthenuts 32on` two screwed rods Xed on the end of thecovering casing, enables the valve to be slackened or tightened in position in the casing.

The operation of the device is verysimple and is`r as follows: When thel valve has thrown the substances which lilled it: into the chamber, its pocket only contains the rareied' gases and vapors fromv thedesicjcacation chamber. As soonas the opening of the pocket is againpresented'below thesu'pply conduit or hopper, the materialik is forced by theiatmospheric pressure'into the pocket. The discharge" valve has;V anv analogous construction :This casing however has a passage 28 opening into the chamber Y. Thep'ocket isthus placed in.v communication with this chamber-'before the valve has resumed its charging position. When it arrives in-Athis position eq n ilibrium of pressure is established andthe material falls into the interior under the 'Y iniuen'ce of gravity. lSeveral 'the discharge can be' employed' upon one and? the same apparatus; f l

Figs. 5 and 6 show a valve analogous to that described above but having two nockets. At each rotation there will thus e two charges and two discharges. Outside oi the pockets the two valves have circular eX- ternal channels and longitudinal recesses 29 for avoiding heating by a free circulation of air as is shown also in Fig. 7 with the same object the external casing has lateral extensions for radiating heat (Figs. 7 and 8) or is surrounded by a water jacket in which the water is circulated (Figs. ,5 and 6). For the discharge valves an equilibrium passage 28` is provided as described above. The' drying chamber is maintained at a suitabletemp'erature by means of the steam jacket Z. The external casing has at its up* per part a steam gage a safety valve and a pipe U which connects it to the air pumpk or eXha'u'ster. The vacuum having been established in the chamber Z and consequently in the rotary coiled pipe, in its axle and in the boxesr- Al and B, saturated steam at a 'tennerature below 100O can lbe maintained at will in these spaces, according as the pressure is below-or above atmospheric pressure. lThe heating apparatus 21, placed at the lower p'art of the' chamber Z, forming a boiler is traversed by a hot fluid', steam, water or gas, whichproduces the evaporation of the water.- The'l water condensed in the rotary coil? pipe isieXtracted atv each revolution by the rotation of the helix and reenters atV B into the steaml chamber.` The condensation produced on the walls of the drying chamber drops directly into the same chamber. Insteadof givingY to' the lower part of the steam chamber the volumenecessary for' containing the water and the heating apparatusuthis part can be reduced and al separate boiler can be employed provided with large' tubes communicating withl the chamber. The driving gear of the distributers comprises wheels 4 and 5 driven by the sha-ft lv and? which also drive the shafts 6 and 7 The wheels 5 and 8 on'said shafts by means of the rods'9 and l0 communicate an oscillating movement to the pulleys y11 and l2. Bymean's-of connections jointedor iexible (chains, and'lixed at their ends at a point-'of the rim, the` pulleys 1l andlQ act upon the two pulleys 13 and 14 which arekeyed onv the axles off the-valves. In case valves having two cells areemployed as represented in'Figs. 5

'and' 6, theserotate with a` continuous movement and may be driven directly from the shafts 6 and 7"' by means of chains or pulleys. After filtration the gases and vapors fare discharged to the vacuum chamber of the condensing apparatusA which can be of any kind ordinarily employed.

It is evident that? theinvention is not strictly limited tothe forms of execution For instance, a filter can indicated above.

metallic cables or strips) l be employed having a diiierent form .from that shown, or this device can in certain cases be dispensed with.

I claim:

1. A vacuum drying apparatus for the continuous desicoation of pulverulent materials comprising a drying chamber, a steam jacket surro-unding the same, a rotatable coiled pipe in said chamber, said pipe being in communication with said steam jacket, and means to rotate said pipe.

2. A vacuum drying apparatus for the continuous desiccation of pulverulent materials comprising a drying chamber provided with an eXit for the gases o-r vapors, a rotatable coiled heating pipe in one portion of said chamber, and a iltering device disposed between said heating pipe and said eXit and which the gases are caused to pass bei-ore reaching said exit.

3. A vacuum drying apparatus comprising a drying chamber provided with an eXit for the gases or vapors, means to agitate the material in the drying chamber, a filtering device disposed between said means and said exit and through which the gases are caused to pass before reaching said exit, and means .to dislodge adhering material from said filing with the drying apparatus to introduce the material to said pocket and an outlet through which material is discharged from the pocket when said rotary portion is turned in the casing, and means to equalize the pressure in said pocket and drying apparatus before the pocket is in position to receive material from the drying apparatus. In testimony whereof I aiiiX my signature, in presence of two witnesses.

ALBIN RAVAUTTE. Witnesses:

FERDINAND TALM, Louis CAUVERY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents. Washington, D. C. 

